In Canadian Patent 2,536,075 entitled “Method of conditioning natural gas in preparation for storage”, there is disclosed a method in which natural gas is divided into a primary stream and a secondary stream. Through a series of heat exchanges a temperature of the primary stream is raised in preparation for consumption and a temperature of the secondary stream is lowered in to produce Liquid Natural Gas (LNG).
A serious problem not addressed in this patent is the presence of carbon dioxide (CO2) in the LNG . In the production of LNG , cryogenic temperatures are reached where the carbon dioxide can form dry ice which can plug lines and equipment. When producing LNG at gas pressure letdown stations the carbon dioxide must be removed to prevent the formation of dry ice and plugging of lines and equipment on the production plant. Traditionally, this concern is addressed by employing mol sieves to absorb and remove the carbon dioxide from the LNG production gas stream. These mol sieves are the largest component of a LNG plant and are energy intensive to regenerate. There will hereinafter be described an alternative method of addressing carbon dioxide removal.